Apparatus and method for repairing tissue

ABSTRACT

Assemblies and methods suitable for knotless arthroscopic repair of tissue defects include two fixation members coupled by two limbs of suture comprising a continuous loop. A unidirectional restriction element that can be a preformed locking, sliding suture knot proximate to one of the fixation members, provides tensioning of the repair.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. Pat. No.10,149,675, filed Aug. 15, 2016, entitled Apparatus and Method forRepairing Tissue, which is a continuation of U.S. Pat. No. 9,421,012,filed Jun. 17, 2014, entitled Apparatus and Method for Repairing Tissue,which is a divisional of U.S. Pat. No. 8,790,369, filed Oct. 30, 2009,entitled Apparatus and Method for Repairing Tissue, which claimspriority of U.S. Provisional Application No. 61/228,396. The completedisclosure of the aforementioned related patent application is herebyincorporated herein by reference for all purposes.

FIELD OF THE INVENTION

The invention relates generally to devices and methods for repairingtissue. More specifically, the invention relates to suture anchoringdevices and methods for arthroscopic repair of tissue defects.

BACKGROUND OF THE INVENTION

A variety of injuries and conditions require repair of soft tissuedamage, or reattachment of soft tissue to bone and/or surroundingtissue. For example, when otherwise healthy tissue has been torn awayfrom a bone, such as a shoulder rotator cuff tendon being partially orcompletely torn from a humerus (a rotator cuff tear), surgery is oftenrequired to reattach the tissue to the bone, to allow healing and anatural reattachment to occur. A number of devices and methods have beendeveloped for performing these surgical repairs, some of the moresuccessful methods including the use of suture anchors or, generically,“suture fixation members,” which typically include an anchor body havingone or more suture attachment feature, and a tissue or bone engagingfeature for retaining the suture anchor within or adjacent to the tissueor bone. Depending on the specific injury, one or more suture anchorconnected to, or interconnected by, one or more segment of suture, mayused to perform the repair.

Surgery can also be required when a tear occurs in the substance of asingle type of tissue, for example in the meniscus of the knee (ameniscal tear). One method of repairing such a tear is to stitch itclosed by passing a length of suture through the tissue and tying thesuture. Suture can also be used in conjunction with one or more sutureanchor to repair such tissue tears. Sutures can be fastened to sutureanchors and to tissue using knots tied by the surgeon during a repairprocedure, or using “knotless” devices and methods, where one or moreanchor and one or more suture can be connected and tensioned without thesurgeon needing to tie knots during the surgery. Knotless anchoring isof particular utility for minimally invasive surgeries such asendoscopic or arthroscopic repairs, where the surgeon must remotelymanipulate the suture at the surgical site using tools inserted througha small diameter cannula or endoscopic tube, which can make the knottingprocess difficult and tedious.

Various methods are used to provide knotless anchoring, includinganchors that automatically lock a suture in position as the anchor isdeployed in tissue, anchor components that can controllably lock asuture to the anchor after the anchor is deployed, devices that enable asuture to slide through them in one direction only, and preformed knotsthat can be tightened by the surgeon using a simple tool, or bytensioning one or more suture strand extending from the knot.

While many suture anchoring systems have been developed for repairingtorn tissue, current devices are not without their drawbacks. Some knotsor other anchor components may “stand proud” above the repaired tissue'ssurface especially that surface facing weight bearing contact with bonesuch as the interface between the femur and the meniscus and interferewith movement and healing of, for example, articulating joint tissue, orthe knot's position relative to the anchor or nearby tissue may not befully under the surgeon's control, in some situations providing a lessthan optimal repair. In surgeries where two or more suture anchors arejoined by suture to repair an injury, any knots or joined suturesegments positioned along the suture connecting the anchors to oneanother can become stress points that limit the ultimate strength of thesurgical repair or contribute to surgical trauma.

Accordingly, there remains a need for improved methods and devices forrepairing torn or damaged tissue, and in particular for methods anddevices suitable for arthroscopic repair of torn or otherwise damagedtissue using suture anchors. There also remains a need for methods anddevices that reduce the risk of damage to the tissue being repaired, andthat provide a low profile to eliminate interference with movement andhealing in articulating joints.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides embodiments of sutureanchoring devices and methods for repairing damaged tissue. An apparatusaccording to the present invention comprises first and second fixationmembers, with each of the first and the second fixation members having afirst surface, an opposing second surface, first and second throughopenings defined between the first surface and the second surface. Aflexible element couples the first and the second fixation members, theflexible element having a first end, a second end and a lengththerebetween which extends from the first end, in order, along a firstend section of suture, through the first opening in the first fixationmember from the respective first surface to the respective secondsurface, through the first opening in the second fixation member fromthe respective second surface to the respective first surface, throughthe second opening in the second fixation member from the respectivefirst surface to the respective second surface, through the secondopening in the first fixation member from the respective second surfaceto the respective first surface, and along a second end section ofsuture. The first fixation member has a third through opening definedbetween the respective first and second surface. A sliding, locking knotis formed between the first end section and the second end section, withthe first end section positioned slidably through the knot and extendingfrom the knot and through the third opening from the first surface tothe second surface.

In one aspect of the invention, the first, second and third openingsthrough the first fixation member are arranged in substantially astraight line along the respective first and second surface. Preferably,the first and the second fixation members comprise rounded surfacesbetween adjacent openings on each respective surface, for sliding theflexible element therealong. In one aspect of the invention each of theopenings has a substantially circular cross section. Alternatively, oneor more of the openings has an elongated cross section. Preferably,tension applied to the second end section with respect to the firstfixation member is effective to decrease a distance between the firstand the second fixation member along the flexible member coupling thefirst and the second fixation member.

In one aspect of the invention, the first and the second fixationmembers further comprises a substantially linear groove in each of therespective first and second surfaces, the groove extending from a firstend of the respective surface to an opposite end of the respectivesurface, the groove in the second surface being substantially parallelto the groove in the first surface. A delivery device has an elongateddelivery member within which at least a portion of each of the first andthe second fixation members, coupled by the flexible element, islongitudinally and slidably received, preferably with their groovesslidably engaged with a slot in the delivery member.

Preferably, the flexible element comprises a suture. In one aspect ofthe invention the flexible element comprises polyethylene. In anotheraspect of the invention the flexible element comprises polyethylene anda bioabsorbable polymer, preferably the bioabsorbable polymer comprisespolydioxanone.

Preferably, the sliding, locking knot is a bunt line knot.

Preferably, a delivery device is provided which comprises a cannulahaving a proximal end and a distal end, and a longitudinal slot in awall of the cannula which extends from the distal end toward theproximal end, the cannula is defined by opposing longitudinal edgesalong the slot. The first and the second fixation device are received inthe cannula along the slot, with the slot edges slidingly engaged inrespective grooves in each of the first and the second fixation device.Preferably, a deployment rod is positioned in the cannula, a handlemechanically couples to the proximal end of the cannula, and a manuallyactuable member is associated with the handle to translate thedeployment rod distally in the cannula for expelling one of the firstand the second fixation device slidingly from the distal end of thecannula.

An apparatus according to the present invention comprises first andsecond fixation members. Each of the first and the second fixationmembers having a first surface and an opposing second surface, first,second and third through openings defined between the first surface andthe second surface of the first fixation device, and one or more throughopenings defined between the first surface and the second surface of thesecond fixation device. A flexible element couples the first and thesecond fixation members. It has a first end, a second end and a lengththerebetween, the length extending from the first end, in order, along afirst end section of suture, through the first opening in the firstfixation member from the respective first surface to the respectivesecond surface, through at least one of the one or more opening in thesecond fixation member from the respective second surface to therespective first surface, through the second opening in the firstfixation member from the respective second surface to the respectivefirst surface, and along a second end section of suture. A sliding,locking knot is formed between the first end section and the second endsection, the second end section extending from the knot and through thethird opening from the first surface to the second surface.

An apparatus according to the present invention comprises first andsecond fixation members coupled by two continuous sections of sutureextending therebetween. The first fixation member has a first surfaceand an opposing second surface. The two suture sections are continuouswith one another and slidable through an opening through the secondfixation member. Each of the two sections of suture extend throughrespective first and second through openings in the first fixationmember from the second surface to the first surface. A sliding, lockingknot joins the two continuous sections of suture adjacent to the firstsurface. A third through opening extends between the first surface andthe second surface and one of the two continuous sections of sutureextends from the knot and through the third opening from the firstsurface to the second surface.

An apparatus according to the present invention provides for repairing adefect in a body tissue. It comprises a first fixation member having afirst surface and an opposing second surface, and first, second andthird through openings between the first and the second surface. Asecond fixation member has one or more through openings. The first andthe second fixation members are coupled by a continuous length of suturedefining a loop joined by a sliding, locking knot positionedsubstantially adjacent to the first side of the first fixation member.The loop extends from the knot slidably through, in order, the firstopening in the first fixation member, at least one of the one or moreopenings in the second fixation member, the second opening of the firstfixation member, and returns to the knot. An end section of thecontinuous length of suture extends from the knot and through the thirdopening of the first fixation member from the first side to the secondside. Tensioning the end section with respect to the first fixationmember is effective to shorten the loop.

Preferably, the knot is a bunt line knot, and also preferably the secondsurface is adapted to contact the tissue being repaired, and the knot ismaintained adjacent to the first surface.

A method according to the present invention provides for repairing adefect in a body tissue. The method comprises the steps of: passing afirst fixation member along a first delivery path through the tissue toa first location on a first surface area of the tissue, the firstfixation member having opposing first and second surfaces, a sliding andlocking suture knot adjacent to the first surface, the suture knotcomprising suture, three limbs of suture extending from the secondsurface along the delivery path, the three limbs of suture eachcontinuous with the suture comprising the knot, a first two of the threelimbs together comprising a continuous loop of suture slidinglyconnected to a second fixation member, the loop having a loop length;tensioning at least one of the three sections of suture to deploy thesecond surface against the tissue at the first location; passing thesecond fixation member along a second delivery path through the tissueto a second location on a second surface area of the tissue; andtensioning the third limb of suture to reduce the loop length betweenthe first fixation member and the second fixation member.

Preferably, tensioning the third limb of suture deploys the secondfixation member against the tissue at the second location and alsoapplies a compressive force to reduce the tissue defect.

Preferably, the first fixation member comprises a first, a second, and athird through opening between the first side and the second side, eachof the first, second and third limb positioned through the respectiveopening and the second fixation member comprises two through openings,and the loop passes slidingly through both openings.

In one aspect of the invention, the first location and the secondlocation are on a single surface of the tissue. In another aspect of theinvention the first location and the second location are on opposingsurfaces of the tissue.

An apparatus according to the claimed invention comprises a firstfixation member having opposing first and second surfaces. A sliding andlocking suture knot sits adjacent to the first surface. It comprisessuture, three limbs of which extend from the second surface, arecontinuous with the suture comprising the knot, each of which arepositioned through a respective through opening between the firstsurface and the second surface. A first two of the three limbs togethercomprise a continuous loop of suture slidingly connected to a secondfixation member. The loop has a loop length. The knot is configured sothat tension applied to the third limb with respect to the firstfixation member is effective to reduce the loop length

An apparatus according to the present invention comprises a firstfixation member having opposing first and second surfaces, with first,second and third through openings extending between the first and thesecond surfaces, and respective first, second and third limbs of suturepositioned through the respective first, second and third openings. Thefirst and the third limbs are positioned slidably through the respectivefirst and third opening and the first and the second limbs arecontinuous with one another to form a suture loop extending from thesecond surface. A second fixation member has one or more openingtherethrough with the loop positioned slidably through at least one ofthe one or more openings through the second fixation member. Arestriction element is associated with the first fixation member and isadapted to slidably pass suture therethrough in a first direction, butnot in a second, opposite direction. The first and the third limbs arecontinuous with one passing through the restriction member adjacent thefirst surface. Tension applied to the third limb with respect to thefirst fixation member is effective to reduce the loop length by slidingthe third and the first limb through the respective third and firstopening.

An apparatus according to the claimed invention comprises a firstfixation member and a second fixation member, with at least one openingthrough the second fixation member. Two limbs of suture form acontinuous loop of suture extending from the first fixation member witha portion of the loop positioned slidably through the at least oneopening through the second fixation member. The first fixation membercomprises a restriction element through which an extension of one of thetwo limbs is positioned to pass slidingly in a first longitudinaldirection, but is restricted from sliding in a second, oppositelongitudinal direction. The two limbs and the extension extending from acommon surface of the first fixation member.

An apparatus according to the present invention provides for repairing abody tissue having a surface. The apparatus comprises first and secondfixation members, each of the first and the second fixation membershaving a respective contact surface adapted to be positioned in contactwith the tissue surface. A continuous loop of suture extends betweenrespective contact surfaces of the first and the second fixation member,the loop having a length, and being slidably positioned through one ormore opening through the second fixation member. A tensioning limb ofsuture extends from the contact surface of the first fixation member sothat tension applied to the tensioning limb with respect to the firstfixation member is effective to reduce the length of the loop.

Preferably, the tensioning limb is continuous with the suture comprisingthe loop. In one aspect of the invention the first fixation membercomprises a locking, sliding knot through which the tensioning limb ispositioned. Preferably, the sliding knot is position adjacent anon-contact surface on the first fixation member, the non-contactsurface being opposed and opposite to the contact surface. Preferably,the tensioning limb can pass slidingly through the knot in a firstlongitudinal direction along the suture, and is restricted from slidingthrough the knot in an opposite longitudinal direction.

A method according to the present invention provides for repairing adefect in meniscus. The meniscus has a first surface facing anassociated femur and a second, opposing surface away from the femur andaway from a tibia. The method comprises the steps of: placing a firstfixation member against the second surface at a first location adjacentthe defect; placing a second fixation member against the second surfaceat a second location adjacent the defect; arranging a flexible memberbetween the first fixation member and the second fixation member acrossthe defect, the flexible member passing through the meniscus andcomprising a loop upon which the second fixation member is slidablyaffixed and which comprises a slip knot affixed to the flexible memberadjacent the first fixation member beyond the second surface; andtensioning a portion of the flexible member through the slip knot toshorten the loop and close the defect.

Preferably, the first fixation member has a first side and a second sidewith the slip knot abutting the first side and wherein the methodcomprises the step of placing the second side against the second surfaceon the meniscus.

DESCRIPTION OF THE DRAWINGS

This invention is described with particularity in the appended claims.The above and further aspects of this invention may be better understoodby referring to the following description in conjunction with theaccompanying drawings, in which like numerals indicate like structuralelements and features in various figures. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

FIG. 1 is a cross sectional view of an exemplary embodiment of a tissuerepair assembly of the present invention, implanted in a body tissue;

FIG. 2A is a side elevation view of an exemplary embodiment of a tissuerepair assembly of the present invention, disposed on a delivery deviceof the present invention;

FIGS. 2B and 2C are side elevation and top views, respectively, of adistal portion of the delivery tool illustrated in FIG. 2A;

FIGS. 3A-3F are cross-sectional views of an exemplary embodiment of amethod for repairing a tissue defect according to the present invention;

FIGS. 4A-4C are respective top plan, end elevation and side elevationviews of an exemplary embodiment of an fixation member of the presentinvention having three through openings for receiving suture;

FIGS. 5A-5C are top plan, end elevation and side elevation views ofanother embodiment of an fixation member of the present invention havingtwo through openings for receiving suture;

FIG. 6 is a perspective view of a tissue repair assembly of the presentinvention employing the fixation members of FIGS. 4A-4C and FIGS. 5A-5C;

FIG. 7 is a side elevation view of an alternative embodiment of anfixation member of the present invention having three through openingsfor receiving suture;

FIG. 8 is a side elevation view of an alternative embodiment of anfixation member of the present invention having two through openings forreceiving suture;

FIG. 9 is a side elevation view of a further embodiment of an fixationmember of the present invention having one through opening for receivingsuture;

FIG. 10 is a cut-away view taken along lines 10--10 of FIG. 6;

FIGS. 11A-11F are top cut-away views of further embodiments of tissuerepair assemblies of the present invention.

DETAILED DESCRIPTION

Devices and methods of the present invention enable a surgeon toconsistently and reliably repair tissue tears and separations using twofixation members interconnected by continuous segments of suture.Surgeries using the devices of the present invention are performedwithout the surgeon having to tie any suture knots, and are particularlysuitable for performing arthroscopic or endoscopic repairs. Repairsperformed using the present invention leave no knots, suture joints orother potential stress points along the suture interconnecting thefixation devices, reproducibly position any knots away from tissue areasthat are particularly susceptible to post-surgical damage, for example,articulating tissue surfaces. It is to be understood that particulardevices and methods disclosed herein are exemplary and not limiting ofthe present invention, for example, embodiments illustrated herein forrepairing in-substance injuries to soft tissue, such as the meniscus ofthe knee, can be equally applied for repairing partial or complete tearsin another type of soft tissue, or for repairing partial or completeseparations of one type of tissue from another, for example, separationof a tendon or ligament from a bone.

Referring more particularly to the figures, FIG. 1 schematicallyillustrates a cross sectional view of an exemplary embodiment of atissue repair assembly 100 of the present invention implanted in a bodytissue 102, for repairing a defect 104 in the tissue 102. In anexemplary embodiment, the tissue 102 is a meniscus in a knee and thedefect 104 is a meniscal tear. In another embodiment, the tissue 102 isanother type of body tissue. In yet another embodiment, the defect 104is a separation between two different types of body tissue.

The repair assembly 100 is seen to comprise a first fixation member 106,a second fixation member 108 and a continuous flexible element 110interconnecting and extending through the first 106 and the secondfixation member 108. The flexible element 110 can comprise any type offlexible element suitable for implantation and use in making surgicalrepairs, and is hereinafter referred to as “suture.” The suture 110 canbe any type of suture including suture fabricated using naturalmaterials such as silk, and synthetic materials such as polyethyleneterephthalate (PET) or other polyester materials. The suture 110 can bebioabsorbable, partially bioabsorbable, or nonabsorbable, and can have acircular cross section or another cross section. In one embodiment, thesuture 110 is partially bioabsorbable, comprising polyethylene as anonabsorbable component, and polydioxanone as a bioabsorbable component.

The first fixation member 106 is seen to comprise a first tissue-contactsurface 112, a first back surface 114 and a first 116, a second 118 anda third through opening 120 between the first tissue-contact surface 112and the first back surface 114. The second fixation member 108 is seento comprise a second tissue contact surface 122, a second back surface124 and a respective first 126 and second through opening 128 betweenthe respective tissue contact 122 and back surface 124. In anembodiment, one or more of the respective through openings is adaptedfor slidably passing the suture 110 therethrough. In a furtherembodiment, the respective tissue contact and back surfaces betweenadjacent openings through each the first 106 and the second anchor 108are rounded to optimize the slidability of the suture 110 through andamong the respective openings. In one embodiment, the cross section ofeach of the openings is round. In another embodiment, one or more of theopenings is elongated in a direction transverse to a line connecting theone or more opening with an adjacent opening through the respectivefixation member.

The suture 110 is seen to comprise a locking, sliding knot 120 adjacentto the back surface 114 of the first fixation member 106. The suture isseen to comprise a continuous loop section 132 extending from thelocking, sliding knot 130, the loop section 132 comprising a first limb134 and a second limb 136. The first limb 134 is seen to extend from thelocking, sliding knot 130 toward and through the respective firstopening 116 in the first fixation member 106 from the respective backsurface 114 to the respective tissue-contact surface 112, toward andthrough the respective first opening 126 in the second fixation member108, from the respective tissue-contact surface 122 to the respectiveback surface 124. Continuing from the back surface 124 of the secondfixation member 108, the first limb 134 is seen to be continuous withthe second limb 136 in the loop 132, returning through the respectivesecond opening 128 from the back surface 124 to the tissue-contactsurface 122 of the second fixation member 108, toward and through therespective second opening 118 in the first fixation member 106, to thelocking, sliding knot 130, completing the loop 132. In an embodiment,the loop 132 is positioned slidably through each of the respective firstand second opening through each of the first 106 and the second fixationmember 108.

In an embodiment, the second limb 136 is connected fixedly to thelocking, sliding knot 130 and the first limb 134 extends slidablythrough the locking, sliding knot 130, to and continuous with atensioning limb 138 that extends from the locking, sliding knot 130toward and through the third opening 140 from the respective back side114 to the tissue contact side 112 of the first anchor 106. Anapplication of tension to the tensioning limb 138 with respect to thefirst anchor 106 is effective to slidingly draw suture from the loop 132through the respective first opening in the first fixation member, thelocking, sliding knot 130 and the third opening 120, shortening the loop132 as the transmitted tension further draws a portion of the secondlimb 136 slidingly through the respective second 128 and first opening126 in the second fixation member 108. In an embodiment, shortening theloop 132 applies a compressive force for closing the defect 104 in thetissue 102. It is to be noted that for illustrative purposes in FIG. 1,the various suture limbs 134, 136 and 138 are shown laterally separatedfrom one another through the tissue 102, but that in an actual tissuerepair using the tissue repair assembly 100, the various suture limbs134, 136, 138 follow a substantially common path adjacent to one anotherthrough the tissue 102.

FIG. 2A schematically illustrates a side view of an exemplary embodimentof the tissue repair assembly 100, disposed on a delivery device 150 ofthe present invention, the delivery device 150 having a distal end 152and a proximal end 154. The delivery device 150 is seen to comprise asubstantially tubular distal delivery member 156 extending distally froma proximal handle 158. FIGS. 2B and 2C illustrate more detailed views ofa distal portion of the delivery member 156 with the tissue repairassembly 100 disposed thereon, in respective side and top views.

The first 106 and the second fixation member 108, with at least aportion of the suture 110 extending therebetween, are seen to beslidably retained along and at least partially within the deliverymember 156. The delivery device 150 is also seen to comprise at leastone deployment rod 160 distally slidable in the delivery member 156 forsequentially expelling the first 106 and the second fixation member 108distally from the delivery member 156. The handle 158 is seen tocomprise at least one manually actuable trigger 162, actuable fordistally sliding one of the at least one deployment rod 160. In oneembodiment, as illustrated in FIG. 2A, the delivery member 156 comprisesa curve 164 along its length. In another embodiment (not shown), thedelivery member 156 is substantially straight between the handle 158 andthe distal end 152.

In an embodiment, each of the first 106 and the second fixation members108 is slidably retained in a longitudinal slot 166 in the deliverymember 156, the slot 166 extending proximally from the distal end 152toward the handle 158, and having opposing longitudinal edges 168 forslidably retaining the first 106 and the second fixation member 108. Asshown, the deployment rod 160 initially rides underneath the secondfixation member 108 outside of the lumen at the distal end of thedelivery member 156 through which the rod 160 slides. After deploymentof the first fixation member 106, a second trigger 163 is engaged whichcauses a second deployment rod 161 to move distally and push the secondfixation member 108 along the slot into a firing position (the positioninitially occupied by the first fixation member 106) within the lumenand ready to be deployed by the rod 160 when the trigger 162 is engaged.As shown, the delivery member 156 terminates distally in atissue-penetrating tip 170. Alternatively, the delivery member 156terminates distally in a blunt tip. In an embodiment, each of the first106 and the second fixation member 108 is retained on the deliverymember 156 in an orientation that presents a minimum cross section ofthe respective fixation member for insertion into or through tissuealong with the delivery member 156.

A resilient tube 172 is shown in FIG. 2A positioned about the deliverymember 156. Preferably, the resilient tube 172 is fabricated from aresilient, transparent silicone material. The tube 172 is omitted fromFIGS. 2B and C for clarity. The resilient tube is seen to be positionedabout the delivery member 156 along a portion of the delivery memberencompassing the locations along the delivery member 156 of the first106 and the second 108 fixation member and at least a portion of thesuture therebetween. Friction between the resilient tube 172 and thefixation members 106, 108 and suture retained therein, retains the first106 and the second fixation members 108 at predetermined longitudinalpositions along the delivery member 156 before delivery of therespective fixation members to tissue. The resilient tube 172 similarlyprovides suture management for the tissue repair assembly 100 bymaintaining the suture along the delivery member. A distal end 174 ofthe resilient tube 172 provides a soft depth stop for insertion of thedelivery member 156 into tissue before deploying either or both of thefirst 106 and the second fixation member 108

FIGS. 3A-3F illustrate an exemplary embodiment of a method for repairinga tissue defect according to the present invention. First referring toFIG. 3A, the delivery member 156, the tissue repair assembly 100retained thereon, is seen to have been passed through a damaged bodytissue 180 having a first tissue surface 182 and a second tissue surface184, to a first location 186 at the second tissue surface 184, where thefirst fixation member 106 is seen to have been slidingly expelled fromthe distal end of the delivery member 156, positioning the firstfixation member 106 proximate to the first location 186. The damagedbody tissue 180 is seen to comprise a tissue defect 188. In anembodiment, the first location 186 is selected by the surgeon so thatthe completed repair will apply compression to the defect 188. In anembodiment, the tissue defect 188 is a meniscal tear and the compressionis effective to close the tear. It is to be noted that for illustrativepurposes in FIG. 3A through FIG. 3F, as also noted for FIG. 1hereinabove, various suture limbs extending from individual fixationmembers are shown laterally separated from one another through thetissue 180 between the first 182 and the second tissue surface 184, butthat in an actual tissue repair, the various suture limbs, follow asubstantially common path adjacent to one another through the tissue102.

Alternatively, the first fixation member 106 can be expelled from thedelivery member 156 within the material of the damaged body tissue 180,or within or adjacent to a surface of another body tissue. Depending onthe nature and location of the tissue defect 188, the surgeon may electto pass the deployment member 156 to the first location 186 directlythrough the tissue defect 188, adjacent to the tissue defect 188, orthrough another area of tissue where the deployed tissue repair assembly100 will be effective to apply compression across the tissue defect 188.

Now referring to FIG. 3B, the delivery member 156 is seen to have beenretracted from the damaged body tissue 180, leaving the first fixationmember 106 proximate to the first location 186. The first fixationmember 106, while slidably retained on the delivery member 156, presentsa minimum cross section for penetrating tissue. In use, the firstfixation member 106 will toggle so that the respective tissue contactsurface 112 lodges against the second tissue surface 184 at the firstlocation 186, presenting a maximum cross section of the first fixationdevice 106 to resist pullout through the damaged tissue 180.

Now referring to FIG. 3C, the delivery member 156, the second fixationmember 108 still retained thereon, is seen to have been passed a secondtime through the damaged body tissue 180, to a second location 190 atthe second tissue surface 184, where the second fixation member 108 isseen to have been slidingly expelled from the distal end of the deliverymember 156, positioning the second fixation member proximate to thesecond location 190. The criteria by which the surgeon selects thesecond location 190 and the path of the delivery member 156 throughtissue are parallel to the criteria used to select the first location186 and the associated path through tissue. Preferably, each of thefirst 186 and the second location 190 is selected by the surgeon so thatthe completed repair will apply compression to the tissue defect 188.The second fixation member 108 can be expelled from the delivery member156 within the material of the damaged body tissue 188, or within oradjacent to a surface of another body tissue.

Turning to FIG. 3D, the delivery member 156 is seen to have beenretracted from the damaged body tissue 188, leaving the second fixationmember 108 proximate to the second location, and leaving a portion ofthe suture loop 132 comprising the first suture limb 134 and the secondlimb 136 positioned adjacent a spanned section 192 of the first tissuesurface 182. The second fixation member 108, while slidably retained onthe delivery member 156, presents a minimum cross section forpenetrating tissue. Upon expulsion from the delivery member 156, and inresponse to tension applied to one or both of the first limb 134 thesecond limb 136, the second fixation member 108 toggles so that therespective tissue contact surface 122 lodges against the second tissuesurface 184 at the second location 190, presenting a maximum crosssection of the second fixation device 108 to resist pullout through thedamaged tissue 180.

Now turning to FIG. 3E, the tensioning limb 138 is seen to have beentensioned with respect to the first fixation member 106, shortening thesuture loop 132 and applying a compressive force to the tissue defect188. As shown, the tissue defect 188 is a meniscal tear and thecompressive force is effective to close the tear. The portion of thesuture loop 132 adjacent the spanned section 192 of the first tissuesurface 182 remains substantially on the first tissue surface 182 afterthe tensioning. Preferably, the tensioning causes the suture comprisingthe loop 132 to locally compress the first tissue surface 182, so thatno suture is exposed above the remainder of the first tissue surface 182with sufficient tensioning the suture comprising the loop 132 embedsinto the damaged tissue 180 below the first tissue surface 182, so thatno suture is exposed above the remainder of the first tissue surface182.

Now turning to FIG. 3F, the tensioning limb 138 is seen to have beentrimmed at or below the first tissue surface 182, leaving none of thetensioning limb 138 proud of the first tissue surface 182. As shown, thedamaged tissue 180 is a meniscus of a knee, the tissue defect is ameniscal tear, the first tissue surface 182 is the articulating surfaceof the meniscus, the second tissue surface 184 is the peripheral rim ofthe meniscus, and each of the first 106 and the second fixation member108 is deployed in the peripheral meniscal capsule. In other embodiment,two or more tissue repair assemblies of the present invention are usedto repair a tissue defect, or to repair physically adjacent defects in atissue.

The determination by a surgeon of first and second locations for therespective first 106 and second fixation member 108, is dependent onmany factors including, but not limited to the type of tissue comprisingthe defect, the nature and extent of the defect, its location in thetissue, and its proximity to other tissues and other defects that may bepresent near the surgical site. The first and second locations forrespective first and second fixation members can be on a singlecontinuous surface of a damaged tissue. Alternatively, the first and thesecond location are on opposite sides of a tissue defect along a tissuesurface. The first and the second location can be on opposing tissuesurfaces, the tissue defect therebetween. The first location and thesecond location could be on different tissues.

FIGS. 4A-4C schematically illustrate respective top, end and side viewsof an exemplary embodiment of a three-opening fixation member 200 of thepresent invention. In an embodiment, the three-opening fixation member200 is the first fixation member 106 of the tissue repair assembly 100disclosed hereinabove. The three-opening fixation member 200 is seen tocomprise a first body 202 having a respective first surface 204, arespective second surface 206, and three through openings comprising afirst 208, a second 210, and a third opening 212 through the body 202between the respective first surface 204 and second surface 206. In anembodiment, the three-opening fixation member 200 is the first fixationmember 106, the respective first surface 204 is the tissue contactsurface 112 and the respective second surface 206 is the back surface114. The three-opening fixation member 200 is symmetrical about a plane214 between the respective first 204 and second surface 206.Alternatively, the respective first 204 and second surface 206 can beasymmetrical about the plane 214.

Each of the three through openings 208, 210, 212, and one or both of therespective first 204 and second surface 206 adjacent to and therebetweenis smoothly rounded to optimize slidability of suture through andbetween the openings. One or more of the three through openings 208,210, 212 is elongated in a direction perpendicular to a lineinterconnecting the one or more opening with an adjacent one of thethree through openings. Elongation of the one or more opening enhancesthe slidability of suture through the respective opening. The first body202 is also seen to comprise a longitudinal groove 216 on each of therespective first 204 and second surface 206. Each groove 216 is adaptedto slidingly engage with one of the edges 168 of the longitudinal slot166 in the delivery member 156, to retain the three-opening fixationmember 200 in the delivery member 156.

FIGS. 5A-5C schematically illustrate respective top, end and side viewsof a further embodiment of a two-opening fixation member 220 of thepresent invention. In an embodiment, the two-opening fixation member 220is the second fixation member 108 of the tissue repair assembly 100disclosed hereinabove. Analogous to the three-opening fixation 200member in construction, the two-opening fixation member 220 is seen tocomprise a second body 222 having a respective first surface 224, arespective second surface 226, and two through openings comprising arespective first 228 and second opening 230 through the second body 222between the respective first surface 224 and second surface 226. Thetwo-opening fixation member 220 is the second fixation member 108, therespective first surface 224 is the tissue contact surface 122 and therespective second surface 226 is the respective back surface 124. Thetwo-opening fixation member 220 is symmetrical about a respective plane232 between the respective first 224 and second surface 226.Alternatively, the respective first 224 and second surface 226 areasymmetrical about the respective plane 232.

The first 228 and the second through opening 230 in the two-openingfixation member and one or both of the respective first 224 and secondsurface 226 adjacent to and therebetween are smoothly rounded tooptimize slidability of suture through and between the openings. One orboth of the two through openings 228, 230 can be elongated in adirection perpendicular to a line interconnecting the two throughopenings 228, 230 to enhance slidability of suture through therespective openings. The second body 222 is also seen to comprise arespective longitudinal groove 234 on each of the respective first 224and second surface 226. Each respective groove 234 is adapted toslidingly engage with one of the edges 168 of the longitudinal slot 166in the delivery member 156, to retain the two-opening fixation member220 in the delivery member 156.

The three-opening fixation member 200 and the two-opening fixationmember 220 can be fabricated from any biocompatible material, and can beof the same, or of a different composition from one another. In oneembodiment, at least one of the fixation members 200, 220 isnonabsorbable. In one further embodiment, at least one of the fixationmembers 200, 220 is fabricated from polyetheretherketone (PEEK) polymer.In another embodiment, at least one of the fixation members 200, 220 isbioabsorbable.

FIG. 6 schematically illustrates a perspective view of an exemplaryembodiment of a tissue repair assembly 250 of the present inventioncomprising the three-opening fixation member 200 and the two-openingfixation member 220. It has the same construction as the tissue repairassembly 100 disclosed hereinabove, wherein the suture 110 comprises thelocking, sliding knot 130, the first 134 the second 136 and thetensioning limb 138, the first 134 and the second limb 136 comprisingthe suture loop 132.

An engagement portion of the suture 110 is positioned slidingly throughthe locking, sliding knot 130 at a location, hereinafter, a “post” 252along the suture 110, substantially adjacent to the respective secondsurface 206 of the first fixation member 200, between the first 208 andthe third opening 212, the post 252 comprising a slidable transitionbetween the first limb 134 and the tensioning limb 136 along the suture110. Upon tensioning the tensioning limb 138 with respect to thethree-opening fixation member 200 to shorten the loop 132, the locking,sliding knot 130 locks the post 252 therein, substantially preventingthe loop 132 from lengthening again. Locking, sliding knots are wellknown in the surgical art. The locking, sliding knot is a bunt linesliding knot, a type of locking, sliding knot known in the surgicalarts, as well as in other arts such as nautical arts. Preferably itfurther comprises a stopper knot 254 to stabilize a suture tail 256extending from the locking, sliding knot 130. Alternatively, the stopperknot 254 can comprise a single figure eight knot.

The three-opening fixation member 200 and the two-opening fixationmember 220 are preferably each fabricated from PEEK, and the suture 110is a partially bioabsorbable, high strength suture comprising ultra highmolecular weight polyethylene (UHMWPE) and polydioxanone (PDS). Morepreferably, the UHMWPE and PDS suture is an Orthocord™ suture,distributed by Depuy Mitek, of Raynham, Mass.

FIG. 7 through FIG. 9 schematically illustrate top views of variousalternative embodiments of fixation members that can comprise tissuerepair assemblies of the present invention. FIG. 7 illustrates a topview another embodiment of a three-opening fixation member 260 thatresembles the fixation member 200 of FIGS. 4A-4C and FIG. 6, except thatin the three-opening fixation member 260 illustrated in FIG. 7, each ofthree openings 262, 264, 266 through a respective body 268 between arespective first 270 and second surface 272, are circular in crosssection. Similarly, FIG. 8 illustrates a top view another embodiment ofa two-opening fixation member 274 that resembles the fixation member 220of FIGS. 5A-5C and FIG. 6, except that in the two-opening fixationmember 274 illustrated in FIG. 8, each of two openings 276, 278 througha respective body 280 between a respective first 282 and second surface284 are circular in cross section.

FIG. 9 schematically illustrates an embodiment of a single-openingfixation member 286 of the present invention. The single-openingfixation member 286 is seen to resemble the two-opening fixation member274 and the three-opening fixation member 260, but having only a singleopening 288 through a respective body 290 between a respective first 292and second surface 294. With reference to the tissue repair assembly 250comprising the three-opening fixation member 200 and the two-openingfixation member 220, in another embodiment, the two-opening fixationmember 220 is replaced with the single-opening fixation member 286, anda suture loop extending between the three-opening fixation member 200and the single opening fixation member 286, is positioned through thesingle opening 288.

In further embodiment, a fixation member comprising a tissue repairassembly of the present invention comprises one or more through openingsin addition to through openings used to position suture in theconstruction of the tissue repair assembly. In yet another embodiment, asuture loop extending from a substantially three-opening fixation membercomprises two or more fixation members therealong, through each of whichthe suture loop is positioned.

In tissue fixation assemblies of the present invention, suture is passedsubstantially in one longitudinal direction only through a locking,sliding element (a restriction element) associated with a fixationmember from which three limbs of suture extend. The restriction elementcan be any type of restriction element through which suture can pass ina preferred longitudinal direction, and is restricted from passing in anopposite longitudinal direction. In various embodiments, the restrictionelement is a locking, sliding suture knot. In another embodiment, therestriction element comprises one or more opening in the fixation memberadapted to pass a barbed suture having a preferred direction of slidingthrough the one or more opening. In yet another embodiment, therestriction element is a unidirectional passage through or around thefixation member itself.

FIG. 10 schematically illustrates a cross sectional side view of aportion of the tissue repair assembly 250 of FIG. 6, showing across-sectional view of the three-opening fixation member 200, and theportion of a the suture 110 positioned therethrough, with the locking,sliding knot 130 lodged against the second surface 206. The internalsurfaces of the three openings 208, 210, 212 through the three-openingfixation member 200 and the portions of the respective first 204 andsecond surface 206 therebetween are seen to be rounded to optimizesliding of the suture 110 therethrough and therealong, respectively.

Tissue repair assemblies of the present invention can be constructed ina variety of configurations, comprising fixation members of any size andproportions suited to repairing a particular tissue defect, selection ofthe size and type of suture used, and variations in the routing ofsuture with respect to the fixation members. The number of throughopenings required in fixation members used to construct a tissue repairassembly of the present invention is in turn selected based on therouting of the suture. FIGS. 11A-11F schematically illustrate variousalternative embodiments of tissue repair assemblies of the presentinvention, differing in configuration from the embodiments illustratedhereinabove with regard to one or both of suture routing between twofixation members, and the number of openings provided through therespective fixation members. It is to be noted that the total number ofopenings provided through any of the fixation members disclosed hereincan exceed the number of openings required for a particular suturerouting without deviating from the intent or scope of the presentinvention.

FIG. 11A illustrates a first alternative embodiment tissue repairassembly 300 comprising a first fixation member 302 and a secondfixation member 304. The tissue repair assembly 300 of FIG. 11A is alsoseen to comprise a length of suture 306 and a restriction element 308.The restriction element 308 is a locking, sliding knot formed from thesuture 306. The length of suture 306 further comprises a first limb 310continuous with a second limb 312, the first 310 and the second limb 312together comprising a suture loop 314 connecting the first 302 to thesecond fixation member 304. The second limb 312 is substantially fixedlyconnected to the restriction member 308. The second limb 312 extendsthrough the restriction member 308 and is continuous with a suture tail316 that is terminated by a stopper knot 318 as disclosed hereinabove.The first limb 310 is routed slidingly through the restriction member308 and is continuous with a tensioning limb 320. In the variousembodiments disclosed herein, suture is routed through one or moreopening through various fixation members. The suture is generallyslidingly routed through the one or more opening to ensure smoothoperation of the assembly, for deploying the respective fixation membersin tissue, and for sliding suture through the assembly to approximate atissue defect.

The various alternative embodiments illustrated in each of FIG. 11Athrough FIG. 11F comprise the length of suture 306 and componentsthereof, but vary in their routing about and between respective firstand second fixation members. As illustrated in FIG. 11A for the firstalternative embodiment tissue repair assembly 300, the first fixationmember 302 is seen to comprise a first 322, a second 324 and a thirdopening 326 therethrough. The second fixation member 304 is seen tocomprise two openings 328, 330 therethrough. The suture loop 314 is seento be routed through each of the two openings 328, 330 in the secondfixation member 304. The first limb 310 is seen to be routed through thefirst opening 322 in the first fixation member 302 and to therestriction element 308. The second limb 312 is seen to be routedthrough the third opening 326 in the first fixation member 302, and tothe restriction element 308. The tensioning limb 320 is seen to berouted from the restriction element 308 and through the second opening324 in the first fixation member 302. Tension applied to the tensioninglimb 320 with respect to the first fixation member 302 is effective todraw suture through the restriction member 308, thereby decreasing thesize of the loop 314. The tissue repair assembly 300 is seen to resemblethe tissue repair assemblies 100, 250 disclosed hereinabove, except thatin the embodiment of FIG. 11A, the tensioning limb 320 is routed througha central opening in the respective fixation member 302, as opposed tobeing routed through a differently positioned in the earlier disclosedtissue repair assemblies 100, 250.

FIG. 11B illustrates a second alternative embodiment of a tissue repairassembly 332 comprising the first 302 and the second fixation member 304of the embodiment of FIG. 11A, but differing in the suture routing aboutand through the first fixation member 302, and in construction of therestriction element 308. In an embodiment of the tissue repair assembly332 of FIG. 11B, the restriction element 308 is a locking, slidingsuture knot affixed to the first fixation element 302 by the suture tail316 being routed through the third opening 326 in the first fixationdevice 302 and secured therethrough by the stopper knot 318. Each of thefirst 310 and the second limbs of suture 312 are seen to be routedthrough one of the first 322 and the second openings 324 in the firstfixation member 302. Further, in the embodiment of FIG. 11B, thetensioning limb 320 is seen to be routed around the first fixationmember 302, as opposed to being routed through an opening in the firstfixation member 302, as illustrated for the first alternative embodimentof the tissue repair assembly 300 illustrated in FIG. 11A.

FIG. 11C illustrates a third alternative embodiment of a tissue repairassembly 334. The tissue repair assembly 334 of FIG. 11C is seen tocomprise a first fixation member 336 having a first 338 and a secondopening 340 therethrough. The tissue repair assembly 334 is also seen tocomprise a second fixation member 342 having a single opening 344therethrough. The suture loop 314 is seen to be routed through thesingle opening 344 in the second fixation member 342, and each of thefirst 310 and the second limb 312 of suture is seen to be routed throughone of the first 338 and the second opening 340 in the first fixationmember 336. As in the suture routing illustrated for the embodiment ofFIG. 11B, the tensioning limb 320 is seen to be routed around the firstfixation member 336.

A fourth alternative embodiment of a tissue repair assembly 346 isillustrated in FIG. 11D. The tissue repair assembly 346 illustrated inFIG. 11D resembles the tissue repair assembly 334 illustrated in FIG.11C, except that in the embodiment illustrated in FIG. 11D, thetensioning limb 320 is routed from the restriction element 314, throughthe second opening 340 in the first fixation member 336. In addition,one of the first 310 and the second limb of suture 312 is seen to berouted through the first opening 338 in the first fixation member 336,and the other of the first 310 and the second limb of suture 312 is seento be routed around the first fixation member 336.

FIG. 11E illustrates a fifth alternative embodiment of a tissue repairassembly 348 comprising a first 350 and a second fixation member 352each having a single respective opening 354, 356 therethrough. In thisembodiment, the suture loop 320 is seen to be routed through the singleopening 356 in the second fixation member 352. One of the first 310 andthe second limb of suture 312 is seen to be routed through the singleopening 354 in the first fixation member 350, and the other of the first310 and the second limb of suture 312 is seen to be routed around thefirst fixation member 350. In addition, the tensioning limb 320 is seento be routed around the first fixation member 350.

FIG. 11F illustrates a sixth alternative embodiment of a tissue repairassembly 358 comprising a first 360 and a second fixation member 362,each having two respective openings 364, 366, 368, 370 therethrough. Thesuture loop 314 is seen to be routed through each of the two openings368, 370 in the second fixation member 362 and each of the first 310 andthe second suture limb 312 is routed directly to the restriction member308, which is positioned adjacent to the first fixation member 360,between the first 360 and the second fixation member 362. Therestriction element 308 is a locking, sliding suture knot affixed to thefirst fixation member 360 by the suture tail 316 being routed throughone 366 of the two respective openings 364, 366 in the first fixationdevice 360 and secured therethrough by the stopper knot 318. Thetensioning limb 320 is seen to be routed through the other 364 of thetwo respected openings 364, 366 in the first fixation device 360.

It is to be noted that in any of the embodiments disclosed herein, anyof the embodiments of respective second fixation members can be combinedwith any of the embodiments of respective first fixation members,associated restriction elements and suture routing to provide additionalembodiments within the intent and scope if the present invention.

Tissue repair assemblies and methods of the present invention haveseveral advantages. A meniscal repair procedure using a tissue repairassembly of the present invention can provide a finished tissue repairwhere only suture, no hard bodies or knots, are left on the articulating(that surface facing the femur) surface of the meniscus in the knee,thus supporting healing and minimizing the probability that articulatingcartilage contacting the meniscus will be damaged when the patientflexes the knee joint after the surgery. Also advantageously, therepairs can be performed in any orientation with respect to a damagedtissue and the associated tissue defect. Tissue repair assemblies of thepresent invention provide additional flexibility for the surgeon becausethe tissue repair assemblies include no fixed lengths of suture to limitthe relative locations of the two tissue fixation members. For example,a repair performed using the tissue repair assemblies of the presentinvention do not restrict the minimum distance between the two fixationmembers. Importantly, using tissue repair assemblies of the presentinvention, an entire meniscal repair can be performed from thearticulating side of the meniscus, an approach that minimizes surgicaltrauma to surrounding tissue.

Another advantage is that the strength and stability of a repairperformed using tissue repair assemblies of the present invention isprovided by two uninterrupted, continuous limbs of suture, the limbsincluding no joints, knots, or retainers therealong between first andsecond anchoring members. Further advantageously, providing two suturesthat completely span the anchoring locations provides superiordistribution of forces on the repaired tissue, relative to single,knotted or joined suture segments spanning the anchoring locations.

Tissue repair assemblies of the present invention are also veryversatile in their application, including applicability to meniscalrepairs, approximation of partial shoulder rotator cuff tears, and anyother soft tissue repair where two tissues, or damage within a tissue,requires surgical approximation. In addition, by pre-drilling one ormore hole in bone for insertion of the delivery member, the tissuerepair assemblies could be used to anchor soft tissue to bone

While the invention has been particularly shown and described withreference to specific preferred embodiments, it should be understood bythose skilled in the art that various changes in form and detail may bemade therein without departing from the spirit and scope of theinvention as defined by the appended claims.

What is claimed is:
 1. An apparatus comprising: first and secondfixation members, each of the first and the second fixation membershaving a first surface, an opposing second surface, first and secondthrough openings defined between the first surface and the secondsurface; a flexible element coupling the first and the second fixationmembers, the flexible element having a first end, a second end and alength therebetween, the length extending from the first end, in order,along a first end section of suture, through the first opening in thefirst fixation member from the respective first surface to therespective second surface, through the first opening in the secondfixation member from the respective second surface to the respectivefirst surface, through the second opening in the second fixation memberfrom the respective first surface to the respective second surface,through the second opening in the first fixation member from therespective second surface to the respective first surface, and along asecond end section of suture; the first fixation member furthercomprising a third through opening defined between the respective firstand second surface; a sliding, locking knot formed between the first endsection and the second end section, the first end section positionedslidably through the knot, the first end section extending from the knotand through the third opening from the first surface to the secondsurface; a substantially linear groove in each of the respective firstand second surface, each groove extending from a first end of therespective surface to an opposite end of the respective surface, thegroove in the second surface being substantially parallel to the groovein the first surface; and a delivery device, the delivery devicecomprises a cannula having a proximal end and a distal end, alongitudinal slot in a wall of the cannula, the slot extending from thedistal end toward the proximal end, the cannula comprising opposinglongitudinal edges along the slot, the cannula receiving the first andthe second fixation device along the slot, with the edges slidingengaged in the respective grooves in the first and the second fixationdevices.
 2. The apparatus according to claim 1 wherein the first, secondand third openings through the first fixation member are arranged insubstantially a straight line along the respective first and secondsurface.
 3. The apparatus according to claim 1 wherein the first and thesecond fixation members comprise rounded surfaces between adjacentopenings on each respective surface, for sliding the flexible elementtherealong.
 4. The apparatus of claim 1 wherein each of the openings hasa substantially circular cross section.
 5. The apparatus of claim 1wherein one or more of the openings has an elongated cross section. 6.The apparatus according to claim 1 wherein tension applied to the secondend section with respect to the first fixation member is effective todecrease a distance between the first and the second fixation memberalong the flexible member coupling the first and the second fixationmember.
 7. The apparatus according to claim 1 wherein the flexibleelement comprises a suture.
 8. The apparatus according to claim 1wherein the flexible element comprises polyethylene.
 9. The apparatusaccording to claim 1 wherein the flexible element comprises polyethyleneand a bioabsorbable polymer.
 10. The apparatus according to claim 9wherein the bioabsorbable polymer comprises polydioxanone.
 11. Theapparatus according to claim 1 wherein the sliding, locking knot is abunt line knot.
 12. The apparatus according to claim 1 furthercomprising a deployment rod positioned in the cannula, a handlemechanically coupled to the proximal end of the cannula, and a manuallyactuable member associated with the handle, the actuable member actuableto translate the deployment rod distally in the cannula for expellingone of the first and the second fixation device slidingly from thedistal end of the cannula.